Antarctic Ozone Hole Shrinks 30 Percent

polar red sends us news of a story that many outlets have picked up from a European Space Agency press release: the Antarctic ozone hole is 30% smaller than it was during the previous record year. It's still about the size of North America. "Scientists say this year's smaller hole... is due to natural variations in temperature and atmospheric dynamics... and is not indicative of a long-term trend. 'Although the hole is somewhat smaller than usual, we cannot conclude from this that the ozone layer is recovering already,' [one researcher said]."

Comments

Environmental spin

[Hal_Porter]

Very strange effect. It seems like lots of studies are done. The ones that show drastic environmental collapse are reported very widely. In this case the news seems good and there isn't an alternative study so we get the comment 'Although the hole is somewhat smaller than usual, we cannot conclude from this that the ozone layer is recovering already'. So the studies may be ok scientfically but picking the outliers which show immininent catastrophe and if that is impossible adding comments that the catastrophe might still be present is not.

So bad news is bad news. Good news means we can't conclude anything.

It reminds me of the 'worst headline ever' : 'Small earthquake : not many killed'. If you want to attract attention, I guess you need a bit of drama.

But maybe I'm complacent and we'll all die of avian flu or global warming or a meltdown in the financial markets causing a collapse of our civilisation.

Also unreported by the major media

[Kohath]

Also unreported by the major media is the new crack in the consensus on ozone depletion in general. There are new indications that the mechanism scientists told us was destroying ozone might not be doing what they thought.

This is the only info available because the press won't report it and I don't have a subscription to the journal "Nature".

Re:Also unreported by the major media

[Anonymous Coward]

Well since I do have a subscription to Nature magazine, let me summarize it briefly:

They report on careful measurements of the photolysis of Cl2O2, which has been a key reaction in ozone climate models for a long time. The measurements indicated that the photolysis reaction was much slower than previously believed (~1/10th the speed). If this is true, then it of course has a significant impact on the ozone component of climate models. The article reports that this would mean that instead of being able to account for nearly all the observed loss of ozone, we can only account for 40% of it.

This is only a single study, however, so it needs to be double-checked by other labs. But, it is coming from a very trustworthy source (NASA JPL), so the climatology community is taking the results seriously. They are now searching for other chemical pathways (both involving and not involving the previous candidates, such as CFCs) that can help explain the observed changes in ozone.

This new knowledge will certainly help in refining climate models to better predict both future trends and possible outcome scenarios for various ranges of human behavior. It should be noted, however, that other evidence (besides the reaction rate models that have now been brought into question) links CFCs and halons with atmospheric ozone, so any future explanation must reconcile all of those observations. Moreover this new study doesn't change the overall picture that is emerging about anthropogenic links to climate.

This new study is certainly important. But science is complicated, requiring hundreds of studies to prove any particular point to the satisfaction of the community. So we should be careful to draw any conclusions from this one study until it has been verified and reconciled with other data.

Re: Conspiracy Theory! ... what are you smoking?

[MillionthMonkey]

You have got to be kidding! We changed our behaviour and it worked? In such a short time frame? You know what? That's utter BS and most climatologists would concur.

It may not be conclusive that the hole shrank because of what we did, but we definitely reduced the stratospheric CFC concentrations:

There are no sinks for CFCs in the lower atmosphere. As a result they are transported to the stratosphere (10 to 50km altitude) where they are broken down by UV radiation, releasing free chlorine atoms which cause significant ozone depletion. In 1998 global atmospheric concentrations of on of the CFCs, CFC-11 was 268pptv. Over the past few decades CFCs 11,12 and 113 have increased more rapidly (on a percent basis) than any other greenhouse gas, but there is now clear evidence that growth rates of CFCs have slowed significantly in the aftermath of the Montreal Protocol (1985) to prevent ozone depletion. In fact, the 1998 atmospheric concentration of CFC-11 was lower than the concentration 5 years earlier. The total forcing value for Chlorofluorocarbons is +0.3Wm-2. This includes CFC-11, 12, 113, 114, 115, methylchloroform and carbon tetrachloride. Under the Montreal Protocol, the production of CFCs 11, 12 and 113 has been successfully phased out since 1995. However, despite these measures, the concentration of CFCs in the atmosphere will remain significant into the next century because of the relatively long lifetimes associated with these compounds.

There's probably better stuff to be Googled up but I'm going to be late for work.

But they spend better than half their time screaming "M-Fer, I want more research funding". Or so my 15 years in academia and government research leads me to believe.

I find your credentialism unconvincing- in fact you don't know how many years I have over you. I've been involved in those filings myself and am familiar with what happens. What I find offensive are the accusations that the entire scientific consensus on the issue is attributable to a desire for research funding. Most scientists do not receive funding for climate research. And it's not as if climate research dollars are even in short supply- after all, allocating that money and "waiting until the results are in" is basically how the president has dealt with all these problems.

Re:Tell me something...

[Anonymous Coward]

I am old enough to remember this. The "second ice age" and "over population" folks were pretty much one-in-the-same. That started in the 60's. I can still remember the TV commercials when I was a kid crying about over populating the planet; "We'll all be a doublin' in thirty-two years". From the same time period I can remember newspaper articles whining about the coming second ice age; "It's already getting colder!". Both congealed into the air/water pollution crowd in the 70's. The 80's saw the same groups briefly trotting out over population once again to add to their pollution sideshow. Then they discovered "ozone depletion". In the late 80's and 90's it was "global warming". Now it's "catastrophic climate change". In *all* cases it's been the same group of people screaming; "the sky is falling".

Re:Conspiracy theory

[jayteedee]

When then in YOUR universe, you haven't been paying much attention to ozone hole research. They have been predicting that the hole would take 30-100 years to recover. BUT, more importantly, their models don't predict this kind of behavior. Which DIRECTLY brings into question their models in most if not ALL areas of ozone hole research. We, as scientist/engineers/etc, don't expect perfect models, but this kind of errant behavior signals a huge OOPS to the other scientists. Look at the 1st chart here: http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17436 (NOTICE this is a NOAA chart) and see that the average and the hardly vary by 30%, but what the article states is "Antarctic ozone hole is 30% smaller than it was during the previous RECORD year". My emphasis. 5-10% beyond a record year would be acceptable. 30% beyond a record year (which yields 60-70% beyond the average) is a BIG DEAL. At least some of the models are suspect, end of story (unless you doing politics, then make up your own story).

You've got your numbers reversed

[Ambitwistor]

but what the article states is "Antarctic ozone hole is 30% smaller than it was during the previous RECORD year". My emphasis. 5-10% beyond a record year would be acceptable. 30% beyond a record year (which yields 60-70% beyond the average) is a BIG DEAL. 30% beyond the record year is not 60-70% beyond the average: you're confusing the signs. The current hole is 30% SMALLER than last year's LARGEST size — i.e., closer to the average size.

We've seen interannual jumps of 30% in ozone hole size before (e.g., here); it's within the range of natural variation, and as such, does not indicate some total failure of the models.